Medical implants are used for a variety of treatments in human body. An example of a medical implant is a stent which is like an artificial tube, inserted into a natural passage in the body to prevent, or counteract, a disease-induced, localized flow constriction. One or more of such stents may be placed into blocked arteries in a body in order to flush out blockage and rejuvenate the working of the blocked arteries. The medical implants are usually coated with a medical drug before being placed in a body part that needs to be treated. With time, the drug is gradually released from the surface of the medical implant into the body part. For example, a drug coated peripheral or coronary stent is placed into narrowed, diseased peripheral or coronary artery and the drug is slowly released to control the blockage.
Typically, pharmaceutical industries use coating apparatuses that implement coating processes for coating bare stents with medical drugs. Commonly known coating processes include spray coating and immersion coating of liquid medical drugs on the stents. Quality of coating is defined in terms of the degree of uniformity of the drug layer coated on a stent. Thus, for obtaining drug coatings of a substantially good quality, the drug has to be coated on the stent with substantial uniformity.